As a method for realizing reduced bit cost of a nonvolatile semiconductor memory device and also enhancing memory performance thereof, scaling down of a memory cell is promising. However, scaling down of the memory cell has become technically difficult.
It has thus been proposed to use organic molecules for a charge storing layer. Because, various organic molecules can be formed by organically synthesize a variety of molecular structures and substituent groups, desired electrochemical properties can be applied to the organic molecules. And constitutional unit of the organic molecules is small. Therefore, the organic molecules may realize further scaling-down of the memory cell. In realizing the scaling-down of the memory cell, it is of importance to improve qualities of a block insulating film and a control gate electrode, formed on the charge storing layer.